DPS Weapon Cast Times
I was super bored at work so I decided to try to measure the cast times of all the (relevant) DPS weapons (I'm missing a few limited weapons, apologies for that). I tested them on bahamut ex 3 so there was no network interference that could throw off the results, but the results are also just a rough estimate based on what I could see by eye (I didn't record them and measure frame by frame or anything too crazy).
The "ATB" is based on how many ATB bars gained from when you click the ability until exactly when the ability can be recast, it's not based on when the damage actually occurs, since some abilities deal their damage very quickly but still take a long time for their animation to finish before they can be recast.
People have always talked smack about how slow Edged Wings is but in reality it's not that bad, and its DPS would only be truly impacted if Young Seph was hasted during overspeed, if he's hasted during ATB conservation, or during overspeed with ATB conservation active, but even then the DPS loss is still minimal.
Any weapon with an animation above 1.4 ATB would lose DPS if the character has overspeed on, is hasted, AND has ATB conservation active, because each ability would cost 2 ATB and the "ATB" section would be multiplied by 1.5x because of haste.
OG Seph always loses DPS while his overspeed is active because he simply cannot cast any of his DPS weapons quick enough to match the extremely low 1 ATB cost.
I included the averages for Cloud and Tifa's weapons without Murasame and Motor Drive in brackets because those are some pretty insane outliers and the only weapons that take under 1 ATB to fully cast.